This invention is related to nibbling machines which follow the outline of a template to progressively nibble away the edge of a sheet metal workpiece until it conforms to the template edge, and more particularly to a nibbling machine in which the template is clamped in surface-to-surface contact with the sheet metal workpiece such that the template edge slideably engages the side of the punch as it is being reciprocated in the die.
Several commercially available machines employ a punch that is reciprocated at the rate of several strokes per second to nibble away the edge of a sheet metal workpiece until it corresponds to the outline of a template. Usually the template is supported above the workpiece. However, in some applications the template is clamped to the workpiece. In the latter applications, the die is supported on a base while the punch and the drive motor are mounted on a "C" shaped frame above the die. The "C" shaped frame limits the type of work that can be cut to that which can be received in the throat between the upper and lower frame arms. For example, if the workpiece has a turned-up edge having a dimension greater than the height of the throat, it is difficult to engage the workpiece with the punch.